TWI766935B - Coating film removal device, coating film removal method, and storage medium - Google Patents

Abstract

An object of the invention is to suppress the occurrence of humps at the edges of a coating film when using a removal liquid to remove the periphery of a coating film formed on a surface of a wafer serving as the substrate. In the removal of unwanted film from the periphery of a coating film by discharging a removal liquid from a removal liquid nozzle 3 onto the periphery of a wafer W rotated by a spin chuck 11, the supply position of the removal liquid is moved from a peripheral position to a cut position which is positioned inside the peripheral position, while the wafer W is rotated at a first rotational speed of at least 2,300 rpm. Then, within one second of the supply position reaching the cut position, the supply position is moved back from the cut position towards the peripheral side of the wafer W. By rotating the wafer W at a fast rotational speed of at least 2,300 rpm, a large centrifugal force acts on the flow of the removal liquid, forcing the removal liquid toward the outside of the wafer W. As a result, infiltration of the edges of the coating film by the removal liquid is suppressed, preventing the occurrence of humps at the edges of the coating film.

Description

Coating film removing device, coating film removing method, and recording medium

The present invention relates to a coating film removing apparatus, a coating film removing method, and a recording medium for removing the peripheral edge portion of a coating film formed on the surface of a circular substrate with a removing liquid.

In one part of the photo-etching process for forming the pattern of the coating film on the substrate, that is, on the semiconductor wafer (hereinafter referred to as the wafer), there is a ring-shaped supply of solvent to the wafer on which the coating film is formed. The edge bead removal (Edge Bead Removal: EBR) process of the film which is unnecessary in the peripheral part of the coating film is removed. In this EBR process, the solvent of the coating film is partially ejected from the solvent nozzle to the peripheral edge portion of the wafer mounted on the spin chuck and rotated.

In this EBR process, when removing the edge film, it is necessary to suppress the occurrence of bulges in the vicinity of the boundary with the film removal region, that is, the edge of the coating film, in order to secure the area for forming the circuit pattern and to improve the yield of the semiconductor device. hump). With the miniaturization of circuits, the photo-etching process is increased, and it is expected that strict requirements for defects in EBR processing will be required, so it is expected to develop a technology that can suppress the generation of bumps.

Patent Document 1 describes a technique in which a solvent is sprayed from a solvent nozzle to dissolve a thin film at the edge of a substrate, and a gas is sprayed from a gas nozzle to a portion where the solvent has been sprayed to blow the solvent away from the edge of the substrate. In this example, the gas is ejected from the gas nozzle to the solvent from the obliquely rear and upper side. Therefore, when this method is applied to the EBR process, the solvent on the coating film is splashed, and the coating film other than the peripheral edge of the wafer is also damaged. As a result, there is a possibility that the shape of the edge portion of the coating film will deteriorate.

In addition, Patent Document 2 describes a method of correcting the warpage of the substrate by providing a gas ejection portion on the inner side of the peripheral portion of the substrate than the processing liquid supply portion when the processing liquid is to be supplied from the processing liquid supply portion to the peripheral portion of the substrate. technology. When this method is applied to EBR processing, the gas is ejected from a position closer to the outer edge of the wafer than the solvent on the coating film, so it cannot be expected to improve the shape of the end of the coating film near the solvent supply area. [Prior Art Documents] [Patent Documents]

[Patent Document 1] Japanese Patent Laid-Open No. 6-196401 (Fig. 3, etc.) [Patent Document 2] Japanese Patent Laid-Open No. 2012-99833 (paragraph 0031, etc.)

[Problems to be solved by the invention]

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a region capable of suppressing the removal of the coating film when the peripheral portion of the coating film formed on the surface of the circular substrate is to be removed with a removal liquid. In the vicinity of the boundary, that is, the technique of producing a bulge at the end of the coating film. [Technical means to solve the problem]

The coating film removing apparatus according to the present invention removes the peripheral edge portion of the coating film formed by supplying the coating liquid to the surface of the circular substrate by the removing liquid, and is characterized by comprising: a rotation holding portion that holds and a rotating substrate; a removal liquid nozzle for ejecting the removal liquid toward the downstream side in the rotation direction of the substrate, and for ejecting the removal liquid to a peripheral portion of the surface of the substrate held by the rotation holding portion; and a control portion for outputting a control signal so that the removal liquid is ejected When the substrate rotates at a speed of 2300 rpm or more.

In addition, the coating film removal method of the present invention is a coating film removal method for removing a peripheral portion of a coating film formed by supplying a coating liquid to a surface of a circular substrate by a removal liquid, and is characterized by comprising: The following two procedures: a procedure of holding the substrate horizontally in the holding part; and then, while the substrate is rotated at a speed of 2300 rpm or more, the removal liquid nozzle is directed toward the downstream side of the substrate rotation direction, and is ejected to the peripheral edge of the substrate surface Procedure for removing fluid.

Furthermore, the recording medium of the present invention records a computer program for the coating film removing apparatus, and the program is characterized by including a group of steps for executing the coating film removing method of the present invention. [Inventive effect]

According to the present invention, when the peripheral portion of the coating film on the surface of the substrate is to be removed by the removing liquid, the removing liquid is ejected from the removing liquid nozzle to the peripheral portion of the substrate surface, and the substrate is rotated at a rotational speed of 2300 rpm or more when the removing liquid is ejected. The substrate rotates at a high speed of 2300 rpm or more, so that a large centrifugal force is applied to the flow of the removal liquid on the wafer surface, so that the removal liquid is pushed to the outside of the wafer W. Thereby, the penetration of the removal liquid to the end of the coating film is suppressed, and the occurrence of bulging at the end of the coating film is suppressed.

(first embodiment)

An embodiment of the coating apparatus 1 to which the coating film removing apparatus of the present invention is applied will be described with reference to the longitudinal side view of FIG. 1 and the plan view of FIG. 2 . The coating apparatus 1 is configured to perform a process of applying a coating liquid to a substrate, that is, a wafer W to form a coating film, and an EBR process. The wafer W is circular and its diameter is, for example, 300 mm. In addition, a groove N is formed in the peripheral portion of the wafer W as a notch indicating the direction of the wafer W. As shown in FIG.

In the drawings, reference numeral 11 is a spin chuck for forming a rotary holding portion that holds and rotates the wafer W. As shown in FIG. The spin chuck 11 is configured to hold the central portion of the back surface of the wafer W to hold the wafer W horizontally, and is rotatable clockwise when viewed in plan along the vertical axis by the rotation mechanism 21 . The spin chuck 11 and the rotation mechanism 21 are connected by a shaft 211 , and a cup body 22 is provided around the wafer W held on the spin chuck 11 . The cup body 22 is configured to be exhausted through the exhaust pipe 23 , and the liquid overflowing from the wafer W into the cup body 22 is removed by the liquid discharge pipe 24 .

For example, the exhaust pipe 23 is connected to the exhaust pipe in the factory, namely the exhaust mechanism 232, through the exhaust volume adjusting part 231 composed of baffles, and is configured to adjust the pressure in the cup. In the figure, reference numeral 25 is an ejector pin, and is configured to be moved up and down by the lift mechanism 26 so that the wafer W is transferred between the wafer W transfer mechanism and the spin chuck 11 .

The coating apparatus 1 includes a coating liquid nozzle 41 that discharges the coating liquid vertically downward, and a solvent nozzle 42 that discharges a solvent of the coating liquid, that is, a solvent vertically downward. The coating liquid nozzle 41 is connected to a coating liquid supply mechanism 44 that supplies the coating liquid to the nozzle 41 through a flow path 43 provided with an on-off valve V1 . The solvent nozzle 42 is a nozzle for preprocessing before the coating liquid is ejected to the wafer W, and is connected to a solvent supply mechanism 46 for supplying a solvent to the nozzle 42 through a flow path 45 provided with an on-off valve V2. As shown in FIG. 2 , the coating liquid nozzle 41 and the solvent nozzle 42 are supported by an arm 48 which is vertically movable by a moving mechanism 47 and is movable in the horizontal direction, so as to be connected to the cup at the center of the wafer W. The body 22 can move freely between the withdrawal positions outside the body 22 . In the figure, reference numeral 49 is a guide rod for moving the moving mechanism 47 in the horizontal direction as described above.

Furthermore, the coating apparatus 1 is provided with the removal liquid nozzle 3 used for performing this EBR process. The removal liquid nozzle 3 ejects the removal liquid toward the peripheral edge portion of the surface of the wafer W held by the spin chuck 11 toward the downstream side in the rotation direction of the wafer W. The removal liquid nozzle 3 is formed, for example, in a straight tube shape, and the front end thereof is opened as a discharge port 30 for the removal liquid.

In this example, the removal liquid is the solvent of the coating liquid, that is, the solvent. The removal liquid nozzle 3 is configured to be connected to the solvent supply mechanism 46 through the flow path 31 provided with the on-off valve V3, and from the common solvent supply mechanism 46, the solvent (removal liquid) is supplied to the solvent nozzle 42 and the removal liquid nozzle 3 independently of each other. In addition, as shown in FIG. 2 , the removal liquid nozzle 3 is supported by an arm 33 configured to be movable up and down by the moving mechanism 32 and movable in the horizontal direction, so as to be configured to eject the removal liquid to the processing position of the wafer peripheral portion. It can move freely between the withdrawal position outside the cup body 22 . In FIG. 2 , the Y direction indicates the moving direction of the removal liquid nozzle 3 and the X direction indicates the horizontal direction orthogonal to the Y direction. In the figure, reference numeral 34 is a guide rod for moving the moving mechanism 32 in the horizontal direction as described above.

As shown in FIG. 3 , when the removal liquid nozzle 3 is viewed from above, the straight line connecting the discharge port 30 of the removal liquid nozzle 3 and the supply position P and the angle θ formed by the tangent to the wafer W at the supply position P are set, for example, at 0°. The included angle θ is preferably a small included angle from the viewpoint of suppressing splashing of the liquid. That is, the tangent line L at the supply position P is preferably aligned with the discharge direction of the removal liquid, but it is more preferably within 6°. The supply position P of the removal liquid refers to a landing position when the removal liquid ejected from the removal liquid nozzle 3 reaches the wafer surface. In FIG. 3 , a portion of the outer edge Lw of the wafer W is indicated by a solid line, and a tangent line L of the wafer W at the supply position P and the discharge direction of the removal liquid are indicated by a broken line.

4, when the removal liquid nozzle 3 is viewed from a vertical plane, the angle Z formed by the straight line connecting the removal liquid nozzle 3 and the supply position P and the surface of the wafer W is set to, for example, 10°. The included angle Z is preferably small from the viewpoint of suppressing splashing of the liquid. Therefore, it is preferably 20° or less, but more preferably 15° or less. Furthermore, the diameter A of the discharge port 30 of the removal liquid nozzle 3 is set to, for example, 0.15 mm to 0.35 mm, or preferably 0.15 mm to 0.25 mm.

Furthermore, the coating apparatus 1 includes a control unit 7 . The control unit 7 is composed of, for example, a computer, and has a program storage unit (not shown). The program storage unit stores a program including commands (groups of steps) that can perform a coating film formation process and an EBR process to be described later. However, according to the program, control signals are output from the control unit 7 to each part of the coating device to control the operation of each part of the coating device 1 . Specifically, the operations of the following devices are controlled, the opening and closing of the on-off valves V1 to V3, the moving mechanisms 32 and 47 to move the removal liquid nozzle 3, the coating liquid nozzle 41, and the solvent nozzle 42, and the exhaust volume adjustment mechanism 231 to move the cup The adjustment of the pressure in the body 22, the lifting and lowering of the ejector pin 25 caused by the lifting mechanism 26, and the like. For example, the program is stored in the program storage unit in a state of being recorded on a recording medium such as a hard disk, an optical disk, a magneto-optical disk, or a memory card.

In addition, in the present example, the control unit 7 is configured to output a control signal for executing the first step and the second step during the EBR process. The first step is to move the supply position P of the removal liquid from the peripheral position of the surface of the wafer W to the center of the wafer W from the peripheral position while the wafer W is rotating at a first rotation speed of 2300 rpm or more A step of ejecting the removal liquid from the removal liquid nozzle 3 at the same time as the cutting position of the coating film. A bevel portion W1 is provided on the peripheral edge of the wafer W, but in this example, the peripheral position is a portion of the flat surface on the inner side of the bevel portion W1, and is closer to the edge (boundary with the bevel portion) from the flat portion by 0.1 The position on the inner side of mm~0.3mm. In the second step, after the supply position P reaches the dicing position, the removal liquid nozzle 3 is separated from the dicing position to the peripheral side of the wafer W within 1 second, preferably within 0.5 second.

Furthermore, the control unit 7 is configured to output a control signal for setting the supply position P between the dicing position and the peripheral position or the peripheral position after the second step, so that the wafer W rotates at a second rotation speed lower than the first rotation speed. The step of ejecting the removal liquid from the removal liquid nozzle 3 while rotating the rotation speed. In the second position, the second rotational speed is set to, for example, 500 to 2000 rpm.

Next, the coating film forming process (coating film forming step) and the EBR process (EBR step) performed by the coating apparatus 1 will be described. First, the transfer wafer W is placed on the spin chuck 11 by a transfer mechanism (not shown). For example, the inside of the cup body 22 is exhausted at an exhaust pressure of 65 Pa, and the solvent is sprayed from the solvent nozzle 42 to the center of the wafer W. On the other hand, the wafer W starts to rotate, and the solvent is applied to the wafer by centrifugal force. on the entire surface of W to improve the wettability of the coating solution on the surface of wafer W. Then, in the state where the wafer W has been rotated, a coating liquid (photoresist liquid in this example) is ejected from the coating liquid nozzle 41 on the center portion of the wafer W, and the coating liquid is applied by centrifugal force. on the entire surface of wafer W. Then, the wafer W is rotated for a predetermined time to dry the liquid film, and the coating film 10 is formed.

Afterwards the EBR step is performed. In this process, for example, the exhaust gas volume in the cup body 22 is set to an exhaust pressure of 50 Pa or more (for example, 75 Pa) larger than that in the coating film formation step. However, as shown in FIG. 5( a ), the first step is performed by moving the removal liquid nozzle 3 from the evacuation position outside the wafer so that the supply position of the removal liquid becomes the peripheral position. However, while the wafer W is rotating at the first rotation speed of 2300 rpm or more, the supply position P of the removal liquid is moved from the peripheral position to the dicing position, that is, the first position, at a flow rate of, for example, 20 ml/min to 60 ml/min ( Preferably, the removal liquid is ejected from the removal liquid nozzle 3 at a flow rate of 55 ml/min or more ( FIG. 5( b )). The first position (dicing position) in this example is, for example, a position closer to 2 mm from the outer edge of the wafer W toward the center portion side of the wafer W. FIG. In addition, on the drawings, in order to achieve technical understanding, priority is given to the proportions of dimensions not necessarily displayed correctly.

In the first step, in order to prevent the occurrence of hump at the end of the coating film, the wafer W must be rotated at a speed of 2300 rpm or more, but it is preferably 2500 rpm or more, more preferably 3000 rpm or more, and 4000 rpm or more The above is the best. In addition, the upper limit of the rotational speed of the wafer W in the first step is, for example, 5000 rpm.

Then perform step 2. That is, immediately after the supply position P of the removal liquid reaches the dicing position (for example, there is no waiting time), the removal liquid nozzle 3 is moved from the first position to the peripheral edge side of the wafer W. No waiting time means, for example, even if the waiting time is not included in the moving recipe of the removal liquid nozzle 3, the removal liquid nozzle 3 stops at the cutting position in terms of the operation of the driving mechanism, for example, for about 0.1 to 0.5 seconds (0.1 in this example). seconds) status. It is necessary to move the removal liquid nozzle 3 to the peripheral edge side immediately after the supply position of the removal liquid reaches the first position. Immediately means, for example, within 1 second. Therefore, for example, this step is a step in which the removal liquid nozzle 3 is separated from the peripheral edge side of the wafer W without substantially stopping after the removal liquid supply position P reaches the dicing position.

The removal liquid is ejected from the removal liquid nozzle 3 toward the downstream side in the rotation direction of the wafer W, and the extension line of the removal liquid ejection trajectory is ejected toward the outer side of the peripheral edge portion of the coating film. In addition, since the wafer W rotates at a high rotational speed of 2300 rpm or more, a large centrifugal force is generated, and the flow of the removal liquid is pushed toward the outer side of the wafer W and rapidly flows therethrough. The coating film 10 is softened and dissolved by the removal liquid in the region where the removal liquid is supplied, and the removal liquid containing the dissolved coating film is removed by being pushed toward the outside of the wafer W by a large centrifugal force.

After the second step is performed in this manner, the step of cleaning the slope portion W1 of the wafer end surface is performed. In this step, the supply position P of the removal liquid is set between the first position and the peripheral position or at the peripheral position, and the wafer W is rotated at the second rotational speed, that is, 500 rpm to 2000 rpm (for example, 1000 rpm) from the removal liquid nozzle 3 The step of ejecting the removal liquid (Fig. 5(c)). For example, as shown in FIG. 5( c ), the supply position (second position) of the removal liquid in this step is, for example, a position close to the inner side of the wafer W from the outer edge of the wafer W by 0.5 mm. The second position continues to supply the removal liquid for, for example, 1 second or longer (5 seconds in this example).

The second rotational speed when the removal liquid is ejected to the second position is lower than the first rotational speed when the removal liquid is ejected to the first position. Therefore, the flow of the removal liquid is pushed toward the outside of the wafer W by the centrifugal force at a slower speed than when ejected from the first position, and the liquid splash of the removal liquid ejected to the wafer is suppressed from bouncing off the rotating wafer W. At the same time, the phenomenon flows from the outer edge of the wafer W to the back side. In this way, on the slope portion W1 of the end face of the wafer W, the removal liquid also spreads to the back side, and the components adhering to the slope portion W1 are cleaned by the removal liquid.

After removing the unnecessary peripheral portion of the coating film and cleaning the sloped portion W1 in this way, for example, the exhaust volume is returned to the exhaust volume at the time of coating film formation, the discharge of the removal liquid from the removal liquid nozzle 3 is stopped, and the flow is moved to Standby position (Fig. 5(d)). However, the rotation of the wafer W is stopped, and the wafer W is transported out of the coating apparatus 1 by a transport mechanism (not shown).

According to the above-described embodiment, when the removal liquid is supplied to the peripheral portion of the coating film on the wafer surface to remove unnecessary coating film on the peripheral portion, the wafer W is rotated at 2300 rpm or more when the removal liquid is ejected. As a result, a large centrifugal force is generated, and the flow of the removal liquid is pushed toward the outer side of the wafer W to flow therethrough. Thereby, the removal liquid at the cutting position is suppressed from permeating the end of the coating film and the generation of a force to lift the end of the coating film is suppressed. In this way, the unnecessary peripheral portion of the coating film is removed while suppressing the occurrence of hump at the end portion of the coating film. In addition, it will be understood from the evaluation test described later that the height of the bumps caused by the EBR treatment is reduced regardless of the type of the removal liquid.

In addition, immediately after the supply position P of the removal liquid reaches the dicing position, it moves from the dicing position to the peripheral side within 1 second, for example, so that the removal liquid supplied to the dicing position is directed toward the wafer from the dicing position by a large centrifugal force. The peripheral edge side of W flows quickly, so that the removal liquid at the cutting position is suppressed from permeating to the edge of the coating film, and the formation of bulges is further suppressed. Furthermore, after the supply position P of the removal liquid reaches the cutting position, it is moved from the cutting position to the peripheral edge side within 1 second, thereby shortening the time required for the EBR process and improving the yield.

In addition, during the EBR step, the rotation speed of the wafer W may be high and the cleaning of the bevel portion W1 may be incomplete. However, a cleaning step of spraying the removal liquid at a position outside the cutting position of the coating film can be performed to improve the bevel portion. Cleanliness of W1. In this cleaning step, the second rotation speed is lower than the first rotation speed, and the supply time of the removal liquid at the second position is longer, but the second position is closer to the peripheral edge side of the wafer W than the first position, so that the penetration of the removal liquid into the coating film is suppressed. Ends. In the cleaning step, the magnitude of the second rotational speed, the second position, and the stop time when the supply position is set to the second position are determined so that the slope portion W1 can be sufficiently cleaned while suppressing the occurrence of bulges.

On the other hand, when the rotational speed of the wafer W is increased when the removal liquid is supplied, a liquid splash phenomenon occurs, and the mist of the removal liquid splashed by the liquid splash re-adheres to the wafer W and becomes a mist-like defect (wet particles). This results in an increase in the number of defects in the peripheral portion of the wafer. Therefore, in the above-mentioned embodiment, the included angle of the removal liquid nozzle 3 is optimized, thereby suppressing the liquid splash phenomenon, and as a result, the number of defects is reduced. That is, in the removal liquid nozzle 3 in the present embodiment, the formed angle θ is set within 6°, and the formed angle Z is set within 20°. As a result, the removal liquid nozzle 3 , which is inclined slightly upward from the horizontal plane, ejects the removal liquid onto the surface of the wafer W substantially along the rotation direction. Therefore, when the removal liquid is supplied to the wafer W at a high rotational speed, the impact force when the removal liquid collides with the surface of the wafer W is reduced, and the removal liquid tends to have an affinity with the wafer W, preventing the liquid from splashing. In addition, since splashing of liquid is prevented, the adhesion of wet particles to the peripheral edge of the wafer is also reduced.

Furthermore, in the EBR step, the inside of the cup body 22 can be set to a high exhaust state of 50 Pa or more, for example, so as to improve the wetting of particles. The reason for this is that the removal liquid, which is in the form of mist due to liquid splash, is quickly discharged from the exhaust duct.

Furthermore, it is believed that increasing the rotation speed of the wafer W when supplying the removal liquid reduces the dicing accuracy of the dicing surface of the coating film (the end surface of the coating film at the dicing position), and the dicing surface is rough and smooth in plan view. Therefore, in the present embodiment, the diameter A of the ejection port 30 of the removal liquid nozzle 3 is reduced, that is, set to 0.15 mm to 0.35 mm, thereby increasing the ejection pressure of the removal liquid to remove the coating film at the cutting position. The cutting force of the fluid increases, thereby improving the cutting accuracy of the cutting surface. In addition, in this example, when the supply position P is moved from the peripheral position to the first position (cutting position), the flow rate of the discharge liquid is set to 20 ml/min to 60 ml/min. Thereby, the pressure of ejection of the removal liquid is increased, and the cutting accuracy of the cut surface is further improved.

(Second Embodiment) The present embodiment is different from the above-described embodiments in that the control unit 7 is configured to output a control signal for repeating the first step and the second step a plurality of times. First, as shown in FIG. 6( a ), the removal liquid nozzle 3 is moved from the evacuation position outside the wafer to the peripheral position. However, in a state where the wafer W is rotated at a first rotation speed of 2300 rpm or more, the supply position P of the removal liquid is moved from the peripheral position of the surface of the wafer W to the dicing position, that is, the first position, for example, at a rate of 20 ml/min ~ The removal liquid was ejected from the removal liquid nozzle 3 at a flow rate of 60 ml/min (first step, FIG. 6( b )). Immediately after the supply position P of the removal liquid reaches the cutting position, it is moved from the first position to the peripheral position, for example, within 1 second (second step, FIG. 6( c )). In this second step, that is, the removal liquid is ejected from the removal liquid nozzle 3 at a flow rate of 20 ml/min to 60 ml/min while the wafer W is rotated at the first rotation speed of 2300 rpm or more. In this way, the first step and the second step are repeated a plurality of times (for example, 5 times).

By carrying out the first step and the second step in this way, as described above, the unnecessary peripheral portion of the coating film can be removed while suppressing the occurrence of bulges. In addition, by repeating the first step and the second step, the cutting force for removing the liquid at the coating film position is increased, so that the cutting accuracy of the cut surface is improved, as can be seen from the evaluation test described later. By repeating the first step and the second step, the removal liquid can be easily circulated from the end portion of the wafer W to the back side, and the slope portion W1 can be cleaned. Moreover, like 2nd Embodiment, after repeating 1st process and 2nd process, you may implement the washing|cleaning process of 1st Embodiment.

As already mentioned, the wafer W rotates at a high speed when the removal liquid is ejected, thereby suppressing the occurrence of bulges and removing unnecessary peripheral portions of the coating film. The higher the rotation speed of the circle W, the lower it will be. On the other hand, as the rotational speed of the wafer increases, the phenomenon of liquid splashing tends to occur, defects may occur, and the smoothness of the cut surface tends to decrease. Based on this point, the inventor team found that when the removal liquid was ejected, the wafer W was rotated at a rotation speed of 2300 rpm or more, and compared with the past, it was possible to suppress the generation of bumps and to remove unnecessary peripheral portions. (Example)

Next, the evaluation test of the present invention will be described with reference to FIGS. 7 to 19 . (Evaluation Test 1: Evaluation of the Bump Height) The coating film forming step and the EBR step were performed while the wafer W was rotated at 1000 rpm, 2000 rpm, 3000 rpm, and 4000 rpm. to evaluate. The coating film is set to SOC (Spin On Carbon) material, which is liquid agent A, the removal liquid is set to OK-73 diluent, and the cutting position is set to the inner position 2.5mm away from the outer edge of the wafer. When the stop time was 5 seconds and when the stop time was 0 seconds, the height of the ridge was measured at each rotational speed. The bump height was measured with a height difference measuring device, and the bump height was evaluated for a plurality of wafers W with the height from the coating film as the bump height.

The results are shown in FIG. 7 . In the figure, the vertical axis represents the height of the bump (nm), and the horizontal axis represents the stop time and rotational speed of the removal liquid supply position at the cutting position. The stop time is the mean value of the ridge height at 5 seconds, 724.92 nm at 1000 rpm, 481.31 nm at 2000 rpm, 302.48 nm at 3000 rpm, and 256.49 nm at 4000 rpm. In addition, when the stop time was 0 seconds, the average value of the ridge height was 512.99 nm at 1000 rpm, 312.97 nm at 2000 rpm, 240.76 nm at 3000 rpm, and 209.35 nm at 4000 rpm.

In this way, it was determined that the stop time was 5 seconds and 0 seconds, the higher the rotational speed, the lower the swell height. In addition, it was confirmed that when the rotational speed was the same, the unnecessary film was removed even if the stop time was 0 seconds, and the height of the ridge became low. From this, it can be understood that the increase in the rotation speed will increase the force of the removal liquid supplied to the dicing position toward the outer edge of the wafer W by the larger centrifugal force, and the cutting force of the dicing position will increase, so even if the stop time is 0 seconds. Unnecessary membranes can still be sufficiently removed.

In addition, confirm that the coating film is changed to photoresist, that is, liquid agent B, SOC material, that is, liquid agent C, photoresist, that is, liquid agent D, and SiARC material, that is, liquid agent E, and the removal liquid is changed to OK. -73 thinner and cyclohexanone, when the same evaluation was performed, as in Evaluation Test 1, the higher the rotation speed, the lower the ridge height, and the stop time at the same rotation speed was 0 seconds, and the ridge height became lower. Therefore, it can be understood that the method of the present invention can reduce the height of the bump without depending on the type of the coating film or the removal liquid.

In this way, it was found that the bump height decreases as the rotational speed of the wafer W increases. However, based on the transition of the bump height, the change in the bump height becomes smaller when it exceeds 3000 rpm. Therefore, if the rotational speed is 2300 rpm or more, the bump height can be sufficiently reduced. In addition, it was found that, with regard to the stop time at the supply position, the average value of the height of the ridge was lower when the stop time was 5 seconds and the rotation speed was 3,000 rpm than when the stop time was 0 seconds and the rotation speed was 2,000 rpm. Bulge height.

(Evaluation Test 2: Evaluation of Liquid Splash) The coating film formation step and the EBR step were performed, and the processing state was photographed and evaluated for the presence or absence of liquid splash. At this time, the removed liquid nozzle 3 changed the formed included angle θ to 0°, 8.5°, the formed included angle Z to 10°, 20°, 30°, and changed the ejection flow rate of the removal liquid to 13ml/min, 20ml/min and 30ml/min, perform the same evaluation, and find out the maximum rotation speed that does not produce liquid splash for each case. The coating film was set to Reagent A, the removal liquid was set to OK-73 thinner, the dicing position was set to a position inside 2.5 mm from the outer edge of the wafer, and the stop time of the supply position at the dicing position was set to 10 seconds.

This result is shown in FIG. 8 . In the figure, the horizontal axis represents the maximum rotational speed (rpm) at which no splash of liquid occurs, and the vertical axis represents the included angle (formed included angle θ, Z) and discharge flow rate (ml/min) of the removal liquid nozzle 3 . . The results were determined to compare the angle θ formed by the removal liquid nozzle 3 and the tangent, and the maximum rotational speed would become larger at 0°. Comparing the angle Z formed with the wafer surface, the maximum rotational speed was 10° and 20°. larger than at 30°. From this, it can be understood that by adjusting the formed included angle θ or the formed included angle Z, the splash of liquid can be reduced. In addition, even if the formed angle θ of the removal liquid nozzle 3 is the same as the formed angle Z, the maximum rotational speed is changed by the discharge flow rate. Furthermore, it was confirmed that the coating film was formed on the wafer W having asperities of ±300 μm, the removal liquid nozzle 3 was formed with the formed angle θ being 8.5°, the formed angle Z was 30°, and the formed angle θ was 0°. For the removal liquid nozzle 3 with the included angle Z of 10°, when the EBR treatment is performed respectively, the formed included angle θ is 0° and the formed removed liquid nozzle 3 with the included angle Z of 10° will improve the cutting accuracy.

From the above results, when the formed angle θ is 8.5° and the formed angle Z is 20°, the maximum rotational speed exceeds 2300 rpm. Based on this, it is found that if the formed angle θ is within 6°, by adjusting the ejection flow rate or the formed angle Z, the liquid splash can be reduced even if the maximum rotational speed is 2300 rpm or more, and if the formed angle Z is within 20°, the By adjusting the ejection flow rate or the formed angle θ, the liquid splash can be reduced even if the maximum rotational speed is 2300 rpm or more.

(Evaluation Test 3: Evaluation of Defects) After the coating film formation step was performed, the wafer W was rotated at 4000 rpm, and the removal liquid was ejected from the removal liquid nozzle 3 while moving back and forth between the peripheral edge position and the dicing position of the wafer W One time to carry out the EBR step, the number of defects (wet particles) was extracted by SEM (Scanning Electron Microscope) to evaluate the mist-like defects.

At this time, the angle Z formed by the formed angle θ being 0° is 10°, the diameter A of the ejection port 30 is 0.2 mm, and the formed angle Z is 30°. ° The diameter A of the ejection port 30 is 0.3 mm for the removal liquid nozzle 3. Liquid A for coating film, OK-73 thinner for removing liquid, the exhaust pressure in the coating film formation step was 65Pa, and the exhaust pressure in the cup 22 in the EBR step was 75Pa. In addition, the stop time of the supply position on the cutting position was set to 0 seconds, and the cutting position (cutting width) was changed for evaluation.

The same evaluation was performed on three wafers W under each condition, and the results are shown in FIG. 9 . In the figure, the horizontal axis represents the cutting width and the conditions of the removal liquid nozzle 3 , and the vertical axis represents the number (pieces) of mist-like defects of a size of 50 nm or more. As a result, it was confirmed that mist-like defects were significantly reduced by the removal liquid nozzle 3 in which the formed angle θ was 0° and the formed angle Z was 10°. From the evaluation test 2, it was found that the angle θ formed by the removal liquid nozzle 3 was optimized, thereby reducing the liquid splash, so it was inferred that the mist-like defects were reduced by suppressing the liquid splash.

(Evaluation Test 4-1: Evaluation of Exhaust Pressure) After the coating film formation step, the wafer W was rotated at 4000 rpm, and the removal liquid was ejected from the removal liquid nozzle 3 at the position between the peripheral edge of the wafer W and the dicing position. The EBR step was performed by moving back and forth 60 times, and the number of defects was evaluated by SEM. At this time, the formed angle θ is 0°, the formed angle Z is 10°, and the diameter A of the discharge port 30 is 0.2 mm for the removal liquid nozzle 3 . The photoresist for the coating film is liquid agent B, the removal liquid is OK-73 thinner, the stop time of the supply position at the cutting position is set to 0 seconds, the cutting width is set to 2 mm, and the discharge flow rate is set to 25 ml/min. The exhaust pressure of the cup 22 during the EBR step is processed and evaluated. The reason why the removal liquid nozzle 3 is moved 60 times is that the number of defects increases due to an increase in the number of processes, and the number of defects is increased to more accurately grasp the state of occurrence of defects.

10 , the horizontal axis represents the exhaust pressure in the cup 22 and the vertical axis represents the number of defects of 50 nm or more in size. As a result, it was confirmed that the number of defects decreased as the exhaust pressure in the cup body 22 increased, and that defects occurred when the rotational speed was 4000 rpm and 50 Pa or less.

(Evaluation Test 4-2: Evaluation of Exhaust Pressure) The rotation speed of the wafer W was changed to 3500 rpm, and the other conditions were the same, and the evaluation was performed in the same manner as (Evaluation Test 4-1). The same evaluation was performed on three wafers W under each condition, and the results are shown in FIG. 11 . In the figure, the horizontal axis represents the exhaust pressure in the cup body 22, and the vertical axis represents the number of defects with a size of 50 nm or more. From this result, it was confirmed that a defect occurs when the rotational speed is 3500 rpm and 30 Pa or less.

(Evaluation Test 4-3: Evaluation of Exhaust Pressure) The rotation speed of the wafer W was changed to 3000 rpm, and the other conditions were the same, and the evaluation was performed in the same manner as (Evaluation Test 4-1). The same evaluation was performed on three wafers W under each condition, and the results are shown in FIG. 12 . In the figure, the horizontal axis represents the exhaust pressure in the cup body 22, and the vertical axis represents the number of defects with a size of 50 nm or more. From this result, it was confirmed that a defect occurs when the rotational speed is 3000 rpm and the exhaust pressure is 23 Pa or less.

(Evaluation Test 4-4: Evaluation of Exhaust Pressure) After the coating film formation step, the rotational speed of the wafer W was set to 3000 rpm, 3500 rpm, and 4000 rpm, and the removal liquid was ejected from the removal liquid nozzle 3 from the wafer W at the same time. The EBR step was performed by moving the peripheral edge position to the cutting position once, and the other conditions were the same, and the evaluation was performed in the same manner as (Evaluation Test 4-1). The same evaluation was performed on three wafers W under each condition, and the results are shown in FIG. 13 . In the figure, the horizontal axis represents the exhaust pressure in the cup body 22, and the vertical axis represents the number of mist-like defects having a size of 50 nm or more. As a result, it is considered that defects are more likely to occur when the rotational speed of the wafer W is increased, but the number of defects can be reduced by increasing the exhaust pressure in the cup body 22 . In addition, it was confirmed that the number of mist-like defects was small at high rotational speeds when compared with the same exhaust pressure (75Pa, 90Pa). From this point of view, it is inferred that when the rotational speed is reduced, liquid splashing is likely to occur in the groove portion of the wafer W, which is the reason for the increase in mist defects.

(Evaluation Test 5-1: Evaluation of Slope Part Cleaning) After the coating film formation step, the wafer W was rotated at 4000 rpm, and the stop time at the first position (dicing position) was set to 0 seconds to perform the EBR step, and then the EBR step was performed. The supply position was moved to the second position, the wafer W was rotated at 2000 rpm to perform the cleaning step, the stop time of the second position was changed from 1 second to 5 seconds, and the cleanliness of the bevel portion W1 was checked with the bevel inspection device. The formed angle θ is 0°, the formed angle Z is 10°, the diameter A of the ejection port 30 is 0.2 mm, and the removal liquid nozzle 3 is used. , the cutting position is set to the inner side of 2 mm from the outer edge of the wafer, and the second position is set to the inner side of 0.5 mm from the outer edge of the wafer.

As a result, it is recognized that the cleaning step is performed after the EBR step, thereby improving the cleanliness of the slope portion W1, and prolonging the supply time of the removal liquid at the second position, thereby improving the cleanliness of the slope portion W1. It was confirmed that if the supply time of the removing liquid at the second position was 3 seconds or longer, the stains on the slope portion W1 would be improved.

(Evaluation Test 5-2: Evaluation of Slope Part Cleaning) In the same manner as (Evaluation Test 5-1), the EBR step and the cleaning step were implemented. The stop time at the second position was set to 5 seconds, and the rotational speed (second rotational speed) of the wafer W in the cleaning step and the exhaust pressure in the cup body 22 were changed to check the cleanliness of the slope portion. The coating film was set to liquid agent B, the removal liquid was set to OK-73 thinner, the dicing position was set to the inner side of 2 mm from the outer edge of the wafer, and the second position was set to the inner side of 0.5 mm from the outer edge of the wafer. In addition, the same evaluation was performed for the case where the cleaning step was not performed.

The same evaluation was performed on three wafers W under each condition, and the results are shown in FIG. 14 . In the figure, the horizontal axis represents the processing conditions such as exhaust pressure and rotational speed, and the vertical axis represents the number of defects with a size of 50 nm or more. , the conditions for the stop time of the second position and the second rotational speed are not described in the case where the cleaning step is not performed. In this result, under the conditions of the exhaust pressure of 90 Pa and the second rotation speed of 1000 rpm, there are still wafers with a large number of defects, but the remaining wafers W under the same conditions have a small number of defects, so even if the cleaning step is performed, It can be said that the number of non-recognized defects deteriorated.

In addition, the number of defects having a size of 50 nm or more in the fog state in (Evaluation Test 5-2) was evaluated by defect re-inspection SEM (Defect Review-SEM: Defect Review-Scanning Electron Microscope). The results are shown in FIG. 15 . It was confirmed that even in this case, by implementing the cleaning step, it was not recognized that the number of defects deteriorated.

(Evaluation Test 6-1: Evaluation of Cut Surface) After the formation step of the coating film, the stop time at the cut position was set to 0 seconds to perform the EBR step. At this time, the angle Z formed by the formed angle θ of 0° is 10°, the diameter A of the ejection port 30 is 0.3 mm, and the formed angle Z is 30°, and the formed angle θ is 8.5°. The diameter A of the discharge port 30 is the removal liquid nozzle 3 of 0.3 mm. The coating film was set to liquid agent A, the removal liquid was set to OK-73 diluent, the cutting width was set to 2.5 mm, and the EBR step was performed and evaluated by changing the ejection flow rate and rotation speed. The smoothness of the cut pieces was assessed with a bevel inspection device.

The same evaluation was performed on three wafers W under each condition, and the results are shown in FIG. 16 . In the figure, the horizontal axis represents processing conditions such as discharge flow rate and rotational speed, and the vertical axis represents the smoothness of the cut surface (mm). ), the smaller the number, the less rough the cutting surface is and the higher the smoothness. This result confirms that the removal liquid nozzle 3 with the formed angle θ of 0° and the formed angle Z of 10° will deteriorate the smoothness of the cut surface. improve.

(Evaluation Test 6-2: Evaluation of Cut Surface) Using the removal liquid nozzle 3 with the formed angle θ being 0° and the formed angle Z being 10°, the diameter A of the ejection port 30 was set to 0.3 mm and 0.2 mm, and the other The conditions are the same as those of (Evaluation Test 6-1), and the evaluation is performed for the cut surface. The results are shown in FIG. 17 . In the figure, the horizontal axis represents processing conditions such as the discharge flow rate and the rotational speed, and the vertical axis represents the smoothness (mm) of the cut surface. As a result, it was confirmed that the cut surface smoothness was improved by reducing the diameter A of the ejection port 30 for the removal liquid nozzle 3 with the formed angle θ being 0° and the formed angle Z being 10°. In addition, it is confirmed that it can also be improved by increasing the discharge flow rate.

It is found that when the diameter A of the removal liquid nozzle 3 is 0.3 mm, and the discharge flow rate is 27 ml/min, the smoothness is almost the same when the rotation speed is 3500 rpm and 4000 rpm. Therefore, if the diameter A of the discharge port 30 of the removal liquid nozzle 3 is 0.15 mm~0.35mm is better. In addition, when the discharge flow rate is 20ml/min, the diameter A is 0.3mm and 0.2mm. When the rotation speed is 2900rpm or more, the smoothness is good at 0.2mm. Therefore, the diameter A of the discharge port 30 of the removal liquid nozzle 3 is 0.15mm~0.25mm. In mm, it can be said that the smoothness of the cut surface is sufficiently improved.

(Evaluation Test 6-3: Evaluation of Cut Surface) After the coating film formation step, the wafer W was rotated at 4000 rpm, and the stop time at the cut position was set to 0 to perform the EBR step. After that, the supply position was moved to the second position, the stop time at the second position was set to 5 seconds, and the wafer W was rotated at 2000 rpm to perform the cleaning step. Change the discharge flow rate of the removal liquid in the EBR step and the cleaning step, and check the smoothness of the cut surface. The coating liquid was set to liquid A, the removal liquid was set to OK-73 thinner, the diameter A of the ejection port 30 was set to 0.2 mm, the dicing position was set to the inside of 2 mm from the outer edge of the wafer, and the second position was set to be from the wafer Outer edge 0.5mm inside.

The results are shown in FIG. 18 . In the figure, the horizontal axis is the discharge flow rate, the vertical axis is the smoothness of the cutting surface, Ref is the liquid removal nozzle 3 with the formed angle θ being 8.5° and the included angle Z being 30°, and the stop time at the cutting position is Data obtained when the wafer W rotates at 2000 rpm for 5 seconds. As a result, it was found that the smoothness of the cut surface was improved by increasing the discharge flow rate for the removal liquid nozzle 3 where the formed angle θ was 0° and the formed angle Z was 10°. It was found that the smoothness of the cutting surface was sufficiently improved when the discharge flow rate was 40 ml/min or more.

(Evaluation Test 7: Evaluation of Discharge Flow Rate) With respect to the wafer W that was separated in the same manner as in (Evaluation Test 6-3), the bump height was confirmed with a level difference measuring instrument. The results are shown in FIG. 19 . In the figure, the horizontal axis is the discharge flow rate, and the vertical axis is the bump height (nm). As a result, it was found that there was no possibility that the height of the ridge would be increased by increasing the discharge flow rate.

As described above, in order to reduce the height of the bump, the coating apparatus 1 of the present invention preferably rotates the wafer W at a rotational speed of 2300 rpm or more when the removal liquid is ejected from the removal liquid nozzle 3 . In addition, in the coating apparatus 1, the following items (a) to (g) can be appropriately combined. (a) Execute the first step and the second step (b) Execute the cleaning step (c) Repeat the first step and the second step multiple times (d) The angle θ formed by the removal liquid nozzle 3 and the tangent line is set within 6° ( e) The angle formed between the removal liquid nozzle 3 and the wafer surface is set to be 20° or less (f) The diameter A of the discharge port 30 of the removal liquid nozzle 3 is set to 0.15mm~0.35mm (g) The liquid is removed from the removal liquid nozzle 3 The ejection flow rate is set at 20ml/min~60ml/min

As described above, the coating apparatus 1 can perform the EBR process on the wafer W on which the coating film has been formed by the external apparatus. That is, the coating apparatus 1 may be configured as a dedicated apparatus for performing only the EBR process, and in this case, the coating liquid nozzle 41 and the solvent nozzle 42 do not need to be provided. As a coating solution, it can be applied to dissolve the components of the coating film in a solvent, such as photoresist, SOD material, SOC material, SiARC material, BARC material, or organic film with carbon as the main component, etc. Various coating films of cloth films.

However, for example, in order to form a NAND flash memory in which wirings are formed in a multi-layer called 3D NAND, a coating film such as a resist film may be formed on a wafer W on which a plurality of films are deposited by a coating apparatus. . The wafers W transferred to the coating apparatus in a state where many films are formed in this way may warp into different shapes due to the influence of the processing performed so far or the stress of each film.

However, since the spin chuck 11 of the coating apparatus 1 holds only the central portion of the wafer W, the wafer W that has warped when being transported is processed in a warped state. In view of this, it is preferable that the removal liquid nozzle 3 of the coating apparatus 1 is configured so that the accuracy of the EBR treatment is not lowered due to the warpage. Specifically, in order to suppress the deviation of the distance from the edge of the wafer W to the supply position P (refer to FIG. 3 ) even if the wafer W is warped, and to prevent the dicing width from deviating from the set value, the method described in FIG. The included angle θ of the removal liquid nozzle 3 is set to a value close to 0° (specifically, it is set to, for example, 0° to 5°, more preferably 0° to 3°). In addition, when the dicing width is supplemented, the dicing width is the width of the annular region where the coating film is removed from the surface of the wafer W by the removal liquid ejected from the removal liquid nozzle 3 .

In addition, regarding the angle Z described with reference to FIG. 4 , the deviation between the set ejection position and the actual ejection position due to the warpage of the wafer W closer to 90° is suppressed, and the dicing width is less affected by warpage. However, when the removal liquid is to be ejected to the wafer W rotating at a relatively high speed as described above, since the pressure when the removal liquid adheres to the wafer W as the angle Z approaches 0° can be suppressed, the removal liquid on the surface of the wafer W can be suppressed. The splash suppression effect becomes higher. Therefore, as mentioned above, when the included angle θ is set at 0°~5°, the included angle Z is preferably set at 5°~20°.

The following is a detailed description of the evaluation test performed to confirm the appropriate values of the included angle θ and the included angle Z. This evaluation test measures the warpage amount of the wafer W in advance before the test, and the measurement of the warpage will be described with reference to FIG. 20 . In FIG. 20, the front surface of the wafer W is represented by W1 and the back surface is represented by W2. In the drawing, reference numeral 51 denotes a mounting portion of the wafer W, and the wafer W is mounted so as to support only the peripheral portion of the wafer W from below. Fig. 52 is a laser displacement sensor, which is configured such that the upper part of the wafer W can be moved laterally relative to the wafer W in order to measure the height of each part of the upper surface of the wafer W placed on the placement portion 51 .

As shown in FIG. 20( a ), the height of each part in the surface W1 of the wafer W is obtained in a state where the surface W1 of the wafer W is placed on the placing portion 51 , and the warpage is obtained from the height of the obtained parts. amount (surface warpage). In addition, as shown in FIG. 20( b ), the height of each part in the back surface W2 of the wafer W is obtained in the state where the back surface W2 is placed on the wafer W, and the warpage amount (back surface warpage) is obtained from the height of the obtained parts. quantity). However, the average value of the surface warpage amount and the back surface warpage amount was taken as the warpage amount of the wafer W. FIG. The mounting portion 51 supports only a part of the surface of the wafer W, and the wafer W is deformed by its own weight. Therefore, by calculating the warpage amount of the wafer W from the surface warpage amount and the back surface warpage amount in this way, it is possible to ignore the measurement caused by the self-weight. error. For the surface warpage, for example, measure the heights of multiple points in the surface 1, and calculate the height of the reference plane from the heights of all the points obtained by the least square method, and the height of the highest point among the measured points is relative to the height of the reference plane. The distance and the distance from the height of the lowest point among the points to be measured relative to the reference plane are added together to calculate. The amount of warpage on the back surface was calculated in the same way as the method for calculating the amount of warpage on the front side.

In the evaluation test to be described later, as shown in FIG. 20 , the wafer W in which the height of the entire circumference of the wafer W is higher than the center height when the surface of the wafer W is turned up is described as a concave wafer W. In addition, the wafer W in which the height of the entire circumference of the wafer W is lower than the center height when the surface of the wafer W is turned upward is described as a convex wafer W. In addition, when viewed along the circumferential direction of the wafer W, the wafer W that is warped so that the height of the peripheral edge of the wafer W is positioned above and below the center of the wafer W, respectively, is described as a concave-convex wafer W. .

(Evaluation Test 8) In the evaluation test 8, the EBR process was performed with the dicing width set at 1 mm for the wafers W whose warpage amounts were different from each other. average width. This EBR treatment is performed by one of the three removal liquid nozzles 3 which are set to a set of an included angle θ and an included angle Z and different from each other. One of the three removal liquid nozzles 3 is set to θ=0° and Z=10°, and this nozzle is set to 3-1. The other one of the removal liquid nozzles 3 is set to θ=8.5° and Z=30°, and this nozzle is set to 3-2. The last one of the removal liquid nozzles 3 is set to θ=30° and Z=30°, and this nozzle is set to 3-3. For the wafer W, no warpage, that is, the warpage amount is 0 μm, the warpage amount of the concave wafer W in FIG. 20 is 196 μm, and the warpage amount of the convex wafer W is 232 μm.

The graph in Figure 21 represents the results of Evaluation Test 8. In this graph, the horizontal axis represents the warpage amount of the wafer W (unit: μm), the vertical axis represents the average value of the cutting width (unit: mm), the warpage amount of the concave wafer W is marked with +, and the convex wafer The symbol of the warpage amount of the circle W. Note -. When the nozzle 3-3 is used as shown in the figure, the wafer W is warped, and the average value of the cutting width has a large deviation from the set value of 1 mm. When using the nozzle 3-2 and using the nozzle 3-3, the deviation was suppressed. However, when the warpage amount is +196 μm, the deviation between the average cutting width and the set value of 1 mm is slightly larger than the practical level. When using the nozzle 3-1, when the warpage amount is 0 μm, +196 μm, and −232 μm, the average value of all the cutting widths substantially agrees with the setting value of the cutting width. Therefore, it was confirmed from the evaluation test 8 that the accuracy of the cutting width was effectively improved when the nozzle 3-3 was used when the warpage amount of the wafer W was in the range of +196 μm to 232 μm.

From the results of using the nozzles 3-2 and 3-3 that differ only in the value of θ among the included angles θ and Z, it can be seen that by changing the included angle θ, the variation of the average cutting width caused by the warpage of the wafer W can be suppressed. However, when the nozzle 3-1 of θ=0° is used, the deviation of the average value of the cut width from the set value of the cut width can be sufficiently suppressed. On the other hand, when θ=8.5°, the amount of deviation is slightly larger as described above. Therefore, it is considered that it is a value slightly lower than 0° or more to 8.5°, and specifically, if it is θ=0° to 8.5° as described above, the variation can be sufficiently suppressed. In addition, considering that the value of Z is 10° when the nozzle 3-1 is used, the deviation between the average value of the cutting width and the warpage amount is suppressed, but the nozzles 3-2 and 3-3 with the value of the angle Z of 30° are used. When the deviation is large, the included angle Z is preferably about 10°, for example, preferably 5° to 20° as described above.

(Evaluation Test 9) In the evaluation test 9, using the nozzles 3-1, 3-2 or 3-3 used in the evaluation test 8, EBR was performed on the uneven wafer W with a warpage amount of 428 μm, and the wafer W was measured in For the EBR cut width at each position in the circumferential direction, the maximum value and the minimum value were calculated as the deviation with respect to the cut width. In this evaluation test 9, the setting value of the cutting width was also set at 1 mm.

The graph of FIG. 22 depicts the results of the evaluation test 9, and on the graph, the vertical axis represents the cutting width (unit: mm). There is a deviation (maximum value - minimum value) for the cutting width, and it is 0.041 mm when using Nozzle 3-1, 0.099 mm when using Nozzle 3-2, and 0.205 mm when using Nozzle 3-1. When the nozzle 3-1 is used in this way, the variation in the cutting width is most suppressed. Therefore, it was confirmed from the evaluation tests 8 and 9 that the precision of the dicing width can be improved by using the nozzle 3-1 even when processing any one of the concave wafer W, the convex wafer W, and the concave-convex wafer W.

(Evaluation Test 10) In the evaluation test 10-1, with respect to a plurality of concave wafers W with a warpage amount of 150 μm, EBR processing was performed by changing the included angle θ of the removal liquid nozzle 3 respectively, and the variation of the dicing width was measured. In addition, in the evaluation test 10-2, the EBR process was performed on the plurality of convex wafers W with a warpage amount of 250 μm, respectively, by changing the included angle θ of the removal liquid nozzle 3, and the variation in the dicing width was measured. In the evaluation tests 10-1 and 10-2, the removal liquid nozzle 3 is arranged as indicated by the solid line in the above-mentioned FIG. 3 or FIG. In addition, the removal liquid nozzles 3 are arranged as indicated by the dot-dash line in FIG. In this evaluation test 10, when the included angle θ is set so that the ejection direction of the removal liquid is from the inside to the outside of the wafer W, the number of the included angle θ is appended with a sign of +, and the ejection direction is from the outside to the inside of the wafer W. When the included angle θ is set in the way of , the number of the included angle θ is annotated with the symbol -. 23, a tangent to the wafer W is indicated by L1, and a line parallel to the tangent L1 is indicated by L passing through the supply position P (the attachment position of the liquid agent ejected from the removal liquid nozzle 3 on the wafer W).

The graphs in FIGS. 24 and 25 represent the results of the evaluation tests 10-1 and 10-2, respectively. In each graph, the vertical axis represents the deviation of the cutting width (unit: mm), and the horizontal axis represents the included angle θ. As shown in the figure, as the absolute value of the included angle θ becomes substantially larger, the deviation of the cutting width becomes larger. Practically, it is best to suppress the variation in the cutting width to 0.1 mm or less. In the evaluation tests 10-1 and 10-2, the included angle θ is in the range of -3°~+3°, so the deviation of the cutting width is 0.1mm. Therefore, it was confirmed that when the warpage amount of the wafer W is in the range of +150 μm to −250 μm, by setting the included angle θ in such a range, variation in the dicing width can be suppressed. When the included angle θ is −, the removal liquid may move to the center side of the wafer W than the supply position P, and the dicing width may deviate from the expected value, so the included angle θ is preferably 0° or more. Therefore, the angle θ is best set to 0°~ +3°

1‧‧‧Coating device 11‧‧‧Rotating chuck 21‧‧‧Rotating mechanism 3‧‧‧Removal liquid nozzle 30‧‧‧Ejection port 7‧‧‧Control part W‧‧‧Wafer P‧‧‧supply Location

FIG. 1 is a longitudinal side view showing an embodiment of a coating apparatus to which a coating film removing apparatus is applied. FIG. 2 is a plan view showing the coating apparatus. FIG. 3 is a plan view of a removal liquid nozzle installed in the coating apparatus. Fig. 4 is a longitudinal side view showing the removal liquid nozzle. FIGS. 5( a ) to ( d ) are longitudinal side views showing the action of the coating device. FIGS. 6( a ) to ( d ) are longitudinal side views showing the action of the coating device. FIG. 7 is a characteristic diagram showing the results of the evaluation test. FIG. 8 is a characteristic diagram showing the results of the evaluation test. FIG. 9 is a characteristic diagram showing the results of the evaluation test. FIG. 10 is a characteristic diagram showing the results of the evaluation test. FIG. 11 is a characteristic diagram showing the results of the evaluation test. FIG. 12 is a characteristic diagram showing the results of the evaluation test. FIG. 13 is a characteristic diagram showing the results of the evaluation test. FIG. 14 is a characteristic diagram showing the results of the evaluation test. FIG. 15 is a characteristic diagram showing the results of the evaluation test. FIG. 16 is a characteristic diagram showing the results of the evaluation test. FIG. 17 is a characteristic diagram showing the results of the evaluation test. FIG. 18 is a characteristic diagram showing the results of the evaluation test. FIG. 19 is a characteristic diagram showing the results of the evaluation test. 20(a)-(b) are longitudinal side views of the wafer. FIG. 21 is a characteristic diagram showing the results of the evaluation test. FIG. 22 is a characteristic diagram showing the results of the evaluation test. FIG. 23 is a top view of the aforementioned wafer and the aforementioned removal liquid nozzle. FIG. 24 is a characteristic diagram showing the results of the evaluation test. FIG. 25 is a characteristic diagram showing the results of the evaluation test.

3‧‧‧Remove Nozzle

10‧‧‧Coating film

11‧‧‧Rotary chuck

W‧‧‧Wafer

W1‧‧‧Slope part

Claims (13)

A coating film removing device for removing a peripheral edge portion of a coating film formed by supplying a coating liquid to a surface of a circular substrate with a removing liquid, characterized by comprising: a rotation holding part for holding and rotating the substrate; the removing liquid a nozzle for ejecting the removal liquid to a peripheral edge portion of the surface of the substrate held by the rotation holding portion so that the removal liquid is directed downstream in the rotation direction of the substrate; and a control unit for outputting a control signal for when the removal liquid is ejected Make the substrate rotate at a rotation speed of 2300rpm or more; the control unit outputs a control signal to perform the following two steps: the first step, in the state of the substrate rotating at a first rotation speed of 2300rpm or more, make the supply position of the removal liquid The removal liquid is ejected from the removal liquid nozzle while moving from the peripheral edge position of the substrate surface to the cutting position of the coating film closer to the center of the substrate than the peripheral edge position; and the second step, after the supply position reaches the cutting position , and move away from the cutting position to the peripheral side of the substrate within 1 second. The coating film removal device as described in claim 1, wherein the control unit outputs a control signal for executing the following step: the step is to set the supply position at the cutting position after the second step The removal liquid is ejected from the removal liquid nozzle while the substrate is rotated at a second rotation speed lower than the first rotation speed between the peripheral edge position or the peripheral edge position. The coating film removal device as described in claim 2, wherein the second rotational speed is set to 500 to 2000 rpm. The coating film removing apparatus described in claim 1, wherein the control unit outputs a control signal for repeating the first step and the second step a plurality of times. The coating film removing apparatus according to any one of claims 1 to 4, wherein, when viewed from above, a straight line connecting the discharge port of the removal liquid nozzle and the supply position, and the substrate at the supply position The angle formed by the tangent is set within 6°. The coating film removing apparatus according to any one of claims 1 to 4, wherein, when viewed in a vertical plane, the angle formed by the straight line connecting the removal liquid nozzle and the supply position and the surface of the substrate Set below 20°. The coating film removing device according to any one of claims 1 to 4, wherein the diameter of the ejection port of the removing liquid nozzle is set at 0.15 to 0.25 mm. The coating film removing apparatus according to any one of claims 1 to 4, wherein the discharge flow rate of the removal liquid when the supply position moves from the peripheral edge portion to the cutting position is set to 55 ml/min or more. A coating film removal method is to remove the peripheral portion of a coating film formed by supplying a coating liquid to the surface of a circular substrate by removing a liquid, and is characterized by comprising the following two procedures: The process of holding the substrate horizontally in the holding part; and then, in the state of rotating the substrate at a rotational speed of 2300 rpm or more, the process of spraying the removal liquid from the removal liquid nozzle toward the downstream side of the substrate rotation direction to the peripheral edge of the substrate surface; The coating film removing method further includes a first procedure of moving a supply position of the removal liquid nozzle from a peripheral position of the substrate surface to a position closer to the substrate than the peripheral position while the substrate is rotating at a first rotational speed of 2300 rpm or more The removal liquid is ejected from the removal liquid nozzle at the same time as the cutting position of the coating film in the center part of the leave. The coating film removal method as described in claim 9, comprising the following procedure: after the second procedure, the supply position is set between the cutting position and the peripheral position or at At this peripheral position, the removal liquid is ejected from the removal liquid nozzle while the substrate is rotated at a second rotation speed lower than the first rotation speed. The coating film removal method according to claim 10, wherein the second rotational speed is 500-2000 rpm. The coating film removal method as described in claim 9, wherein the first procedure and the second procedure are repeated a plurality of times. A recording medium recording a computer program for a coating film removing device, The coating film removing device removes the peripheral portion of the coating film formed by supplying the coating liquid to the surface of the circular substrate by removing the liquid, and the computer program is characterized in that it includes executing any of the 9th to 12th items in the scope of the patent application. A step group of the described coating film removal method.

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